feat: preparing migration

routes/assessments.py

@@ -1,6 +1,7 @@
 from flask import Blueprint, render_template, redirect, url_for, flash, request, jsonify, current_app
 from models import db, Assessment, ClassGroup
 from forms import AssessmentForm
+# Import du service avec rétrocompatibilité gérée dans services/__init__.py
 from services import AssessmentService
 from utils import handle_db_errors, ValidationError
 from datetime import datetime